futtern/tests/Entity/FoodOrderTest.php

<?php declare(strict_types=1);

namespace App\Tests\Entity;

use App\Entity\FoodOrder;
use App\Entity\OrderItem;
use PHPUnit\Framework\TestCase;

final class FoodOrderTest extends TestCase
{
    public function testFoodOrder(): void
    {
        $order = new FoodOrder;
        $orderItem = new OrderItem;
        $this->assertCount(0, $order->getOrderItems());
        $order->addOrderItem($orderItem);
        $order->addOrderItem($orderItem);
        $this->assertCount(1, $order->getOrderItems());
        $this->assertSame($order, $orderItem->getFoodOrder());
        $order->removeOrderItem($orderItem);
        $this->assertCount(0, $order->getOrderItems());
        $this->assertNull($orderItem->getFoodOrder());
    }
}